Method for forming metal layer on surface of insulating plastic

ABSTRACT

A method for forming a metal layer on a surface of an insulating plastic, includes attaching metal particles in a selected area of the surface of the insulating plastic, irradiating the selected area with a laser such that the selected area of the insulating plastic is fused to be mixed with the metal particles, and performing chemical plating to the selected area to form a metal layer in the selected area.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 201310241700.5 filed in P.R. China on Jun. 19, 2013, the entire contents of which are hereby incorporated by reference.

Some references, if any, which may include patents, patent applications and various publications, may be cited and discussed in the description of this invention. The citation and/or discussion of such references, if any, is provided merely to clarify the description of the present invention and is not an admission that any such reference is “prior art” to the invention described herein. All references listed, cited and/or discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a method for forming a metal layer on a surface of insulating plastic.

BACKGROUND OF THE INVENTION

In the industry, in a process of manufacturing a structure such as an antenna or a circuit, a metal pattern usually is required to be formed in a local area of a surface of an insulator.

Currently, a generally adopted method includes selecting an insulator containing active metal particles to make a component, ablating a surface of the component by laser, thereby exposing the metal particles in the insulator, and then placing the component treated by the laser into a chemical solution for chemical plating copper or nickel thereon. In the chemical plating process, the exposed metal particles are used as chemical plating medium, and a chemical reaction is initiated on the surfaces of the metal particles between the positive ions of metal copper or nickel and other negative ions, such that the reaction product is deposited on the surfaces of the metal particles to form a metal pattern, i.e., the metal pattern is formed on the surface of the insulator. However, a specially-made insulator material containing active metal particles is required in the foregoing method for manufacturing the metal pattern, and thus the manufacturing cost is high.

Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.

SUMMARY OF THE INVENTION

In one aspect, the present invention is directed to a method for forming a metal layer on a surface of insulating plastic.

In one embodiment, a method for forming a metal layer on a surface of insulating plastic includes step 1: attaching metal particles in a selected area of the surface of the insulating plastic; step 2: performing laser irradiation to the selected area, such that the selected area of the insulating plastic is fused to be mixed with the metal particles; and step 3: performing chemical plating for the selected area to form a metal layer on the selected area.

In one embodiment, before the step 1, surface roughening treatment is performed on the selected area, so as to enhance an attaching force of the metal particles to the insulating plastic.

In one embodiment, the surface roughening treatment includes irradiation through laser or an immersion through a chemical solution. In one embodiment, a method such as spraying, daubing or bonding is adopted, so that the metal particles are attached to the selected area.

In one embodiment, the insulating plastic is immersed in a solution having the metal particles, so that the metal particles are attached to the selected area.

In one embodiment, between the step 2 and the step 3, the method further includes: activating the metal particles.

In one embodiment, after the step 2 and before the step of activating, cleaning the insulating plastic, such that the metal particles on the surface of the insulating plastic except for the selected area are removed. In one embodiment, after the step 3, another chemical plating or electroplating is performed to the metal layer to form a plating layer.

In one embodiment, after the step 2, a part of the metal particles is embedded in the insulating plastic, and a part thereof is exposed on the surface of the insulating plastic. In one embodiment, the metal particles are active.

As compared with the related art, in the method according to certain embodiments of the present invention, a metal layer can be directly formed in the selected area of the surface of the ordinary insulating plastic, and no specially-made insulator material containing metal particles needs to be used, thereby reducing the manufacturing cost. These and other aspects of the present invention will become apparent from the following description of the preferred embodiment taken in conjunction with the following drawings, although variations and modifications therein may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate one or more embodiments of the invention and together with the written description, serve to explain the principles of the invention. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.

FIG. 1 is a flowchart of a method for forming a metal layer on a surface of insulating plastic according to one embodiment of the present invention.

FIG. 2 is a sectional view of attaching metal particles on a surface of insulating plastic according to one embodiment of the present invention.

FIG. 3 is a sectional view of performing laser irradiation to a selected area of the surface of the insulating plastic according to one embodiment of the present invention.

FIG. 4 is a sectional view after performing laser irradiation to the selected area of the surface of the insulating plastic according to one embodiment of the present invention.

FIG. 5 is a sectional view after cleaning the surface of the insulating plastic according to one embodiment of the present invention.

FIG. 6 is a sectional view of a metal layer formed after performing chemical plating for the surface of the insulating plastic according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Various embodiments of the invention are now described in detail. Referring to the drawings, like numbers indicate like components throughout the views. As used in the description herein and throughout the claims that follow, the meaning of “a”, “an”, and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. Moreover, titles or subtitles may be used in the specification for the convenience of a reader, which shall have no influence on the scope of the present invention.

Referring to FIG. 1, in one embodiment, the present invention relates to a method for forming a metal layer 3 on a surface of an insulating plastic 1. The method includes the following main steps.

Referring to FIG. 2, step 1 includes providing the insulating plastic 1, and attaching metal particles 2 on the surface of the insulating plastic 1. The insulating plastic 1 is an ordinary plastic. The metal particles 2 have an activation activity, i.e., they can serve as a medium for chemical plating. The metal particles 2 can be copper particles, palladium particles or other metal particles which can serve as a chemical plating medium. The metal particles 2 can be attached to the surface of the insulating plastic 1 by spraying, daubing or bonding. Alternatively, the metal particles 2 can also be attached to the surface of the insulating plastic 1 in another manner. For example, the insulating plastic 1 can be immersed in a solution having the metal particles 2, so that the metal particles 2 cover the surface of the insulating plastic 1. If the immersion manner is adopted, an air drying treatment is needed after the immersion, such that the metal particles 2 can be fully adsorbed on the surface of the insulating plastic 1.

In order to strengthen an adsorption force of the metal particles 2 to the insulating plastic 1, in one embodiment, before the step 1, surface roughening treatment is performed to the surface of the insulating plastic 1. The surface roughening treatment includes such as irradiation by laser or immersion by a chemical solution. The specific process of coarsening by use of laser irradiation includes: the surface of the insulating plastic 1 can absorb optical energy of the laser, thereby increasing the temperature; further, gasification occurs in the surface to form many tiny and dense holes which enhance the adsorption force of the metal particles 2 to the insulating plastic 1. Therefore, when the insulating plastic 1 is moved, the metal particles 2 do not easily fall off. In terms of immersion by the chemical solution, the surface of the insulating plastic 1 is puffed after the immersion, and the foregoing hole effect is also achieved, so the adsorption force of the metal particles 2 to the insulating plastic 1 can also be enhanced.

Referring to FIG. 3, FIG. 4 and FIG. 6, step 2 includes performing laser irradiation on the selected area, such that the selected area 11 of the insulating plastic 1 is fused to be mixed with the metal particles 2. The selected area 11 is an area where the metal layer 3 needs to be formed. A path of the laser irradiation can be precisely controlled through a computer. In addition, the light spot is very tiny, and the resolution is high, so the selected area 11 formed through the laser irradiation has a high precision. Based on this, the dimensions of the metal layer 3 subsequently formed through the chemical plating has a high precision.

The selected area 11 is treated by the laser irradiation, so that the temperature of the selected area 11 and the temperature of the metal particles 2 are instantaneously increased, and the selected area 11 of the surface of the insulating plastic 1 is formed into a fusing state, thereby being mixed with the metal particles, i.e., enabling the metal particles 2 to be embedded into the insulating plastic 1. When the temperature of the surface of the insulating plastic 1 cools down, a part of the metal particles 2 is embedded into the insulating plastic 1, and a part thereof is exposed on the surface of the insulating plastic 1, thus the metal particles 2 can server as the medium of the chemical plating.

Referring to FIG. 5, after the step 2, the insulating plastic 1 need to be cleaned. Through the cleaning, the metal particles 2 on the surface of the insulating plastic 1 except for the selected area 11 are removed, thereby preventing the metal particles 2 on the surface of the insulating plastic 1 outside the selected area 11 from affecting subsequent chemical plating. The cleaning can be performed through ultrasonic wave, i.e., the insulating plastic 1 is placed in an ultrasonic wave container and cleaned. The metal particles 2 attached in the selected area 11 are embedded in the insulating plastic 1, so the metal particles 2 in the selected area 11 are not removed by cleaning

After the cleaning of the insulating plastic 1 is completed, in one embodiment, activation treatment can be performed to the metal particles 2 in the selected area 11, i.e., an oxidation layer on the surface of the metal particles 2 is removed, so as to prevent the oxidation layer from affecting the chemical plating. Generally, the insulating plastic 1 can be immersed in a sulfuric acid solution at certain concentration, such that the oxidation layer on the surface of the metal particles 2 is removed through chemical reaction.

Referring to FIG. 6, step 3 includes performing chemical plating on the selected area 11, and forming the metal layer 3 in the selected area 11. The selected area 11 is attached with the metal particles 2, and the metal particles 2 can serve as the medium of the chemical plating. During chemical plating, metal ions in the chemical plating solution react on the surface of the metal particles 2, thereby deposit the reaction product on the surface of the metal particles 2 to form a plating layer, i.e., to form the metal layer 3.

In one embodiment, after the step 3, another chemical plating or electroplating is performed on the metal layer 3, so as to form another plating layer (not shown in the drawing). The forming of the another plating layer includes the following situations: the material of the another plating layer is the same as the material of the metal layer 3, thereby increasing the thickness of the metal layer 3, so that the metal layer is wear resistant; alternatively, the another plating layer is made of nickel or another inactive metal material, and can further protect the metal layer 3, so that the metal layer 3 is not easily oxidized in air; alternatively, the another plating layer is made of gold or another metal material with a good conducting performance, and can strengthen the conducting performance of the metal layer 3.

In summary, certain embodiments of the present invention, among other things, have the following beneficial advantages.

1. The metal particles 2 can be attached to the surface of the insulating plastic 1 in variant manners such as spraying, daubing, bonding and immersion, such that in an actual manufacturing process, different selection can be made according to requirements of the manufactured device.

2. Before the step 1, the surface roughening treatment can be performed to the surface of the insulating plastic 1. The surface roughening treatment includes, for example, irradiation by laser or immersion by a chemical solution. Through the surface roughening treatment, the adsorption force of the metal particles 2 to the insulating plastic 1 can be enhanced, so when the insulating plastic 1 is moved, the metal particles 2 do not easily fall off.

3. Laser irradiation is performed to the selected area 11, such that the selected area 11 of the insulating plastic 1 is fused to be mixed with the metal particles 2. The selected area 11 is an area where the metal layer 3 needs to be formed. Since the path of the laser irradiation can be precisely controlled through a computer, the light spot is very tiny, and the resolution is high, the selected area 11 formed through the laser irradiation has a high precision. Accordingly, the size of the metal layer 3 formed subsequently through the chemical plating also has a high precision. Moreover, the path of the laser irradiation can be manually controlled, so that the selected area 11 can be changed according to different manufacturing demands, and the operation can be performed simply and conveniently.

4. After the step 3, another chemical plating or electroplating is performed on the metal layer 3 to form another plating layer. The another plating layer includes the following situations: the material of the another plating layer is the same as the material of the metal layer 3, thereby increasing the thickness of the metal layer 3, so that the metal layer 3 is more wear resistant; alternatively, the another plating layer is made of nickel or another inactive metal material, and can further protect the metal layer 3, so that the metal layer 3 is not easily oxidized in air; alternatively, the another plating layer is made of gold or another metal material with a good conducting performance, and can strengthen the conducting performance of the metal layer 3.

5. The selected insulating plastic 1 is an ordinary plastic, and when the metal layer 3 is formed through this method, no specially-made insulator material containing active metal particles needs to be used, thereby reducing the manufacturing cost.

The foregoing description of the exemplary embodiments of the invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. The embodiments are chosen and described in order to explain the principles of the invention and their practical application so as to activate others skilled in the art to utilize the invention and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein. 

What is claimed is:
 1. A method for forming a metal layer on a surface of insulating plastic, comprising: step 1: attaching metal particles in a selected area of the surface of the insulating plastic; step 2: performing laser irradiation to the selected area, such that the selected area of the insulating plastic is fused to be mixed with the metal particles; and step 3: performing chemical plating for the selected area to form a metal layer on the selected area.
 2. The method of claim 1, wherein before the step 1, surface roughening treatment is performed on the selected area, so as to enhance an attaching force of the metal particles to the insulating plastic.
 3. The method of claim 2, wherein the surface roughening treatment comprises irradiation by laser or immersion by a chemical solution.
 4. The method of claim 1, wherein the step 1 is performed by a method comprising spraying, daubing or bonding, so that the metal particles are attached to the selected area.
 5. The method of claim 1, wherein the insulating plastic is immersed in a solution having the metal particles, such that the metal particles are attached to the selected area.
 6. The method of claim 1, further comprising, between the step 2 and the step 3, activating the metal particles.
 7. The method of claim 6, further comprising, after the step 2 and before the step of activating, cleaning the insulating plastic, such that the metal particles on the surface of the insulating plastic except for the selected area are removed.
 8. The method of claim 1, further comprising, after the step 3, another chemical plating or electroplating is performed to the metal layer to form a plating layer.
 9. The method of claim 1, wherein after the step 2, a part of the metal particles is embedded in the insulating plastic, and a part of the metal particles is exposed on the surface of the insulating plastic.
 10. The method of claim 1, wherein the metal particles are active. 